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>13.4. When the clock is wrong</A
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><P
> The Linux software clock is not always accurate.  It is
	kept running by a periodic <I
CLASS="GLOSSTERM"
>timer interrupt</I
>
	generated by PC hardware.  If the system has too many processes
	running, it may take too long to service the timer interrupt, and
	the software clock starts slipping behind.  The hardware clock
	runs independently and is usually more accurate.  If you boot
	your computer often (as is the case for most systems that aren't
	servers), it will usually keep fairly accurate time.  </P
><P
> If you need to adjust the hardware clock, it is usually
	simplest to reboot, go into the BIOS setup screen, and do it
	from there.  This avoids all trouble that changing system time
	might cause.  If doing it via BIOS is not an option, set the new
	time with <B
CLASS="COMMAND"
>date</B
> and <B
CLASS="COMMAND"
>clock</B
>
	(in that order), but be prepared to reboot, if some part of the
	system starts acting funny.  </P
><P
> A networked computer (even if just over the modem) can
	check its own clock automatically, by comparing it to some other
	computer's time.  If the other computer is known to keep very
	accurate time, then both computers will keep accurate time.
	This can be done by using the <B
CLASS="COMMAND"
>rdate</B
> and
	<B
CLASS="COMMAND"
>netdate</B
> commands.  Both check the time of a
	remote computer (<B
CLASS="COMMAND"
>netdate</B
> can handle several
	remote computers), and set the local computer's time to that.
	By running one these commands regularly, your computer will keep
	as accurate time as the remote computer.  </P
><P
> XXX say something intelligent about NTP </P
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